1. Field of Invention
The present invention relates to an image pipeline, and more particularly to a routable image pipeline device.
2. Related Art
In recent daily life, various digital technologies replacing conventional analog technology have become very popular, and among others, the digital image technology is a good example. In a digital image, values of pixels in the image are recorded in an array form, and the value of each pixel in the image is represented by limited bits.
For example, a digital camera captures an image with an optical sensor and converts the image into a digital signal, and a series of image processing is performed on the digital signal. The most common method for processing the digital image is to apply various filters to the digital image, for example, to process original mono color pixels of the digital image to RGB pixels and YUV pixels sequentially by using filters, or perform various digital image processing such as noise reduction, image sharpening, image tone variation, image brightness variation, or edge detection on the digital image.
In addition, in order to perform the step of digital image processing requiring a plurality of filters, image pipeline architecture emerges. The image pipeline connects the filters to be executed, and provides a line buffer corresponding to each filter respectively, so as to store image pixels. However, the conventional image pipeline has the disadvantages that the line buffer lacks flexibility in use and it is inconvenient in modification and expansion. The length of the line buffer is limited by a scanning mode of accessing the digital image or the length of the digital image, and the number of the line buffers is limited by the size of the corresponding filters, for example, a 3×3 filter or a 7×7 filter. Further, the filters used by the image pipeline are fixed, so the image pipeline can only be used for processing fixed digital images, and thus lacks expandability. Moreover, if the line buffers of the image pipeline are insufficient, the line buffers have to be expanded one by one, which is rather inconvenient.